--- August 1995 "Alien Worlds" Internet Raytrace Competition Entry --------- Name: astplant.jpg Size: 154256 bytes Date: 30AUG95 Author: John P. Beale Email: beale@jumpjibe.stanford.edu Hardware: Pentium-75 with 8 meg ram; HP 9000/712 with 64 meg ram Software: POV-Ray 2.2, gforge 1.1f, HF utilities (see below) Command: gopov astplant +w800 +h600 +a0.2 Memory Used: 59 megabytes Render Time: 52 minutes Comments: The geometric primitives in POV-Ray are convenient for constructing regular shapes and geometries, but it isn't so easy to render natural-seeming landscapes using spheres and planes. Heightfields, or explicit triangle-meshes give you more flexibility, but you need to generate them somehow. In the course of making this image I created a number of utility programs to help me create and manipulate heightfields/meshes: gforge generate landscape heightfields (well, I had already written this) hcon convert between heightfield formats copyx make a heightfield twice as wide composit combine heightfields in many different ways remap distort a heightfield orb convert a TGA to a "spherical heightfield", ie, a triangle mesh ast_gen create a field of asteroids, using adaptive detailing erode carve away a heightfield as if rivers were eroding soil All except the last two are publicly available on my home page, in if you want to use them yourself. Ast_gen is kind of special-purpose, but I can make that available too if you request. Erode has some problems yet and isn't ready for release. The only simple primitives in the scene are the smallest asteroids, which are spheres. Larger asteroids, the moon, and the spiky plant-ball are triangle meshes from 'orb'. The foreground landscape and the plant stem are heightfields. Using high-resolution meshes takes up a lot of memory; the scene uses about 59 meg ram to render; about 1/3 plant-ball and 2/3 asteroids. The heightfields, even though the foreground is 1200x600, are tiny by comparison. (If POV-Ray stored triangle meshes using pointers to the vertices, instead of the explicit vertex each time, it would only need 1/3 the memory.) I developed the scenes and software on my P-75 at home, then used a University workstation to render the more detailed scene files. (The HP 9000/712 is really fast; the speed of a Pentium-150 if such existed, according to a crude floating-point-intensive benchmark I tried on it and a P-120 (gforge -m 1024). All in all I spent a lot more time programming than rendering, but hopefully the utilities will be useful to others, too. The astplant.zip file contains the .pov, a script file that will use the above-mentioned utilities to create all the include files, plus two other heightfields which are necessary, so anyone can regenerate the image at whatever resolution you want. The script is also a good demo of how to use the utilities in your own creations. -john beale beale@jump.stanford.edu